The present invention relates to container closures, and in particular to closures including tamper indication such as a tamper indicating band.
Tamper indicating closures for bottles and other containers are designed to indicate to the consumer when the container has been opened or otherwise tampered with. Known tamper indicating closures typically include a flat, circular closure top and an annular skirt depending downwardly from the outer rim of the closure top. The inner surface of the skirt portion includes threads which interact with a threaded portion of the container neck to retain the closure on the container.
Tamper indicating closures also typically include a tamper indicating band connected to the bottom of the skirt along a frangible line or joint. The tamper indicating band is generally an annular member which may have a plurality of inwardly and upwardly extending tabs that are retained beneath an annular shoulder on the neck of the container. When the closure is removed from the container for the first time, the tabs contact the shoulder and cause the tamper indication band to separate from the skirt along the frangible line.
With many known tamper indicating closures, the closure top, skirt, and tamper indicating band are formed integrally. However, due to the complexity and shape of the tamper indication closure, the tabs must often be formed facing downwardly, and later folded upwards. In some cases, this method of manufacturing may require reheating of the closure to set the tabs in an upward and inward position, adding to manufacturing time and costs.
In an effort to avoid this problem, some closures are formed with foldable arrangements. Known foldable arrangements, however, are often formed as unitary, foldable bands spanning the circumference of the closure, rather than individual tabs (see, for example, U.S. Pat. No. 4,546,892 to Couput). These foldable bands, and similar arrangements in which the foldable bands are broken up into large segments, can be difficult to fold. To the extent folding is achieved, the folding process can bend and deform the relatively large bands and segments, decreasing the structural integrity and hence the reliability of the tamper indicating mechanism. Other foldable closures group a plurality of tabs with bridging elements (see, for example, U.S. Pat. No. 4,981,230 to Marshall et al.). These groups may suffer the same drawbacks as the foldable bands described above. Alternatively, the groups may require relatively weak bridges which can rupture, again decreasing the structural integrity and reliability of the mechanism.
The present invention provides a tamper indicating closure, which includes a top wall, a skirt depending from the top wall, and a tamper indicating band. The tamper indicating band is connected to the skirt along a frangible line. The tamper indicating band includes a ring and a plurality of tabs having a bi-stable geometric shape. Each tab includes a pair of extending members angled toward one another and connected by a transverse member, forming a generally trapezoidal shape. The shape of the tab allows it to be molded in a downward orientation and later folded to a stable, upward orientation, without requiring reheating or other remolding of the closure or tab.